How to do URL Rewrite in Zuul Proxy?

Question

One of the request that comes to my Zuul Filter is of URI /hello/World which i want to redirect to /myapp/test. This /myapp/test is a service that is registered in Eureka.

zuul:
  routes:
     xyz:
         path: /hello/World
         url: http://localhost:1234/myapp/test
         stripPrefix: true

When i try the above configuration, the incoming URI is suffixed to the configured URL like http://localhost:1234/myapp/test/World . Few of the links which i came across seem to be stating that URL Rewrite feature is not yet available in Zuul.

Is there any other way this can be done at the Zuul Layer ?

Note: At this point of time, i cannot do this reverse proxying in the Webserver or any other layer since, my Zuul filter is the one that is receiving the request directly.

Answer 1

Using @Adelin solution, with little improvements

Use 'url' property as path to prepend for customizing the Url rewriting (I have disabled Eureka in my example) :

ribbon.eureka.enabled=false

zuul.routes.route1.path=/route1/**
zuul.routes.route1.serviceId=service1
zuul.routes.route1.url=/path/to/prepend

service1.ribbon.listOfServers=http://server1

Then implement the following filter :

/**
 * Fixing missing URL rewriting when using ribbon
 */
@Component
public class CustomPathZuulFilter extends ZuulFilter {

    @Autowired
    private ZuulProperties zuulProperties;

    @Override
    public String filterType() {
        return FilterConstants.PRE_TYPE;
    }

    @Override
    public int filterOrder() {
        return FilterConstants.PRE_DECORATION_FILTER_ORDER + 1;
    }

    @Override
    public boolean shouldFilter() {
        // override PreDecorationFilter only if executed previously successfully
        return RequestContext.getCurrentContext().getFilterExecutionSummary().toString()
                .contains("PreDecorationFilter[SUCCESS]");
    }

    @Override
    public Object run() {
        final RequestContext context = RequestContext.getCurrentContext();
        if (context.get(FilterConstants.SERVICE_ID_KEY) == null || context.getRouteHost() != null) {
            // not a Ribbon route
            return null;
        }

        // get current ZuulRoute
        final String proxy = (String) context.get(FilterConstants.PROXY_KEY);
        final ZuulRoute zuulRoute = this.zuulProperties.getRoutes().get(proxy);

        // patch URL by prefixing it with zuulRoute.url
        final Object originalRequestPath = context.get(FilterConstants.REQUEST_URI_KEY);
        final String modifiedRequestPath = zuulRoute.getUrl() + originalRequestPath;
        context.put(FilterConstants.REQUEST_URI_KEY, modifiedRequestPath);

        // patch serviceId because :
        // - has been set to route.location in PreDecorationFilter
        // - route.location has been set to zuulRoute.location in SimpleRouteLocator
        // - zuulRoute.location return zuulRoute.url if set
        context.set(FilterConstants.SERVICE_ID_KEY, zuulRoute.getServiceId());

        return null;
    }
}

Now calls to /route1 will be proxified to http://server1/path/to/prepend

This solution is also compatible with co-existing routes not using Ribbon.

Example of a co-existing route not using Ribbon :

zuul.routes.route2.path=/route2/**
zuul.routes.route2.url=http://server2/some/path

Calls to /route2 will be proxified to http://server2/some/path by SimpleHostRoutingFilter (if not disabled)

Answer 2

Here is a posted solution in the link by @Vikash

@Component
public class CustomPathZuulFilter extends ZuulFilter
{
    @Override
    public String filterType() {
        return "pre";
    }

    @Override
    public int filterOrder() {
        return PreDecorationFilter.FILTER_ORDER + 1;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {
        RequestContext context = RequestContext.getCurrentContext();
        Object originalRequestPath = context.get(REQUEST_URI_KEY);
        String modifiedRequestPath = "/api/microservicePath" + originalRequestPath;
        context.put(REQUEST_URI_KEY, modifiedRequestPath);

        return null;
    }
}